Field of the Invention
The present invention relates to a wireless power transmission method and system for preventing frequency interference.
Description of the Related Art
A wireless power transmission system is generally used as a technology for transmitting power between devices that are spaced apart from each other using an induced electromotive force mechanism. In the wireless power transmission system, a known technology is used to enable power to be transmitted between devices arranged separately using a frequency with a specific range which is generally between about 100 and 210 kHz. However, since the wireless power transmission system transmits power using a wireless signal, when other devices using a frequency adjacent to the frequency band of a signal for transmitting power are disposed at a substantially close distance, a malfunction may occur due to frequency interference.
Accordingly, to avoid the frequency interference and collision, a multichannel technology has generally been used in the wireless power transmission system. In a wireless power transmission field, however, a frequency band which is able to be used practically may be limited. Thus, there is a restriction of changing the frequency variously for transmitting power without a wire. Moreover, upon a change of the frequency, power transmission efficiency is consequently varied according to the change of the frequency, and the variation range may be substantially significant.
In another method, a method of shielding electromagnetic waves is used, which reduces a physical area influenced by the electromagnetic waves for the purpose of preventing frequency interference between different devices. The above mentioned method, however, has a disadvantage in that an extra cost is required for additionally installing a shielding member in the electromagnetic wave shielding structure. Moreover, when a wireless power transmission structure needs to be redesigned, the shielding structure applied previously has to be redesigned by re-measuring a radiation pattern whenever a design of wireless power transmitter is changed. Accordingly, there are disadvantages in that the method using the electromagnetic wave shielding is complicated to be developed.